Definition from Wiktionary, the free dictionary
subway (plural subways)
- (Canada, US, Scotland) An underground railway, especially for mass transit of people in urban areas.
- (US) A rapid transit system, regardless of the elevation of its right of way.
- (Britain) An underground walkway, tunnel for pedestrians (called pedestrian underpass in US).
(rapid transit system):
- (intransitive, US, informal) To travel by underground railway.
2008 February 13, Melissa Clark, “From Paris, With Hustle”, in New York Times:
- I suppose I could have subwayed around town in search of froufrou French pastry shops.